A common chip needs to be packaged and then electrically connected with an electronic board to be installed in an electronic device. In particular, an image-sensing chip needs to be protected by a package body and then electrically connected with an electronic board for operation.
FIGS. 1A to 1G show the method for electrically connecting an image-sensing chip like a CCD or a CMOS sensor with an electronic board. First, a ceramic package substrate 10a is prepared. A groove 11a is formed in the upper side of the ceramic package substrate 10a. An image-sensing chip 20a is then adhered in the groove 11a of the ceramic package substrate 10a. Electric connection lines 30a are then used to electrically connect the ceramic package substrate 10a and the image-sensing chip 20a. Next, a transparent board 40a is attached on the upper side of the ceramic package substrate 10a to package the image-sensing chip 20a. A package body 50a having the image-sensing chip 20a is then adhered to an electronic board 60a by means of surface mount technology (SMT). Finally, a lens seat 70a and a lens 80a are then assembled on the package body 50a to finish an image detection module.
FIGS. 2A to 2F show another method for assembling an image-sensing chip into an image detection module. First, a hard PCB 90a is manufactured with a plurality of solder pads 91a thereon. The image-sensing chip 20a is adhered on the upper side of the hard PCB 90a. The electric connection lines 30a are then used to electrically connect the image-sensing chip 20a and the solder pads 91a. The lens seat 70a and the lens 80a are then assembled on the hard PCB 90a to package the image-sensing chip 20a on the hard PCB 90a. The lower end face of the hard PCB 90a has a plurality of electric connection sheets 92a. A soft circuit board 100a having comb-shaped electric connection sheets 101a at two ends thereof is also prepared. The comb-shaped electric connection sheet 101a at one end of the soft circuit board 100a is stained with conducting glue to be pressed and adhered to the electric connection sheet 92a at the lower end face of the hard PCB 90a. The comb-shaped electric connection sheet 101a at the other end of the soft circuit board 100a is also stained with conducting glue to be pressed and adhered to the electronic board 60a or via a connector 93a, thereby forming an image detection module.
However, the above methods for assembling an image-sensing chip into an image detection module have the following drawbacks:                1. Because the price of the ceramic package substrate is high, the material cost is thus increased. Moreover, because it is necessary to connect the package body having the image-sensing chip firmly on the electronic board, the installation flexibility of the package body is thus reduced.        2. Because the comb-shaped electric connection sheet and the electric connection sheet of the hard PCB are glued together with conducting glue on a small area, the adhesion strength is low.        3. When the hard PCB and the soft circuit board having comb-shaped electric connection sheets are glued together, the comb-shaped electric connection sheet may be not completely pressed on the hard PCB due to unevenness of the end face of the hard PCB having the electric connection sheet, hence reducing the adhesion strength. Moreover, it is necessary to use a microscope to view and align the adhesion portion of the two components, hence increasing the manufacturing time and wasting manpower. Also, the conductivity of the conducting glue is reduced after a period of time at room temperature, hence lowering the yield.        